Static Simulation Scheduling for the Validation of Space System Requirement Decomposition

Abstract

One important issue in space engineering is to ensure that all system requirements are always fulfilled throughout the whole development process. To perform this task, various validation technologies have been developed. In this paper, document-based reviews and Modelling & Simulation technology are illustrated as two of such technology examples. Their disadvantages are analysed as well. The fundamental challenge for them is to carry out a consistent validation throughout the whole development process. To resolve this problem, a static simulation scheduling approach is proposed in this paper. This scheduling approach is based on a hierarchical decomposition model of a space system. The model is constructed following the principles of Model-Based Systems Engineering (MBSE). It maps all requirements to state variables and defines states as well as relations along three red lines of a space mission: inter-subsystems, internal subsystems, and space mission lifecycle. In the static simulation scheduling approach, the validation is driven just by the states of state variables and their relations. But, the specific validation process is dependent on current states of the processed variable. The scheduling approach is illustrated and demonstrated in this paper. It facilitates a preliminary validation analysis throughout the whole development lifecycle that would otherwise be cost intensive or even be impossible. Furthermore, after each system refinement, the validation analysis can be performed again automatically. Our work is based on the “Virtual Satellite”, which is being developed by German Aerospace Center (DLR). We are pursuing the possibility to implement specification, analysis, design, and operation of space missions in a unified framework.